Add scrollbars setting

crates/editor/src/editor.rs

@@ -516,6 +516,15 @@ pub struct EditorSnapshot {
     ongoing_scroll: OngoingScroll,
 }
 
+impl EditorSnapshot {
+    fn has_scrollbar_info(&self) -> bool {
+        self.buffer_snapshot
+            .git_diff_hunks_in_range(0..self.max_point().row(), false)
+            .next()
+            .is_some()
+    }
+}
+
 #[derive(Clone, Debug)]
 struct SelectionHistoryEntry {
     selections: Arc<[Selection<Anchor>]>,

crates/editor/src/element.rs

@@ -2058,7 +2058,15 @@ impl Element<Editor> for EditorElement {
             ));
         }
 
-        let show_scrollbars = editor.scroll_manager.scrollbars_visible();
+        let show_scrollbars = match cx.global::<Settings>().show_scrollbars {
+            settings::ShowScrollbars::Auto => {
+                snapshot.has_scrollbar_info()
+                    || editor.scroll_manager.scrollbars_visible()
+            }
+            settings::ShowScrollbars::System => editor.scroll_manager.scrollbars_visible(),
+            settings::ShowScrollbars::Always => true,
+        };
+
         let include_root = editor
             .project
             .as_ref()